I have had A3s on both ends of my bike for a month now. About 800 miles on them so far due to crappy weather. Previously I have run Tourance and A2s.
Some things I noticed. The A3 has a much stiffer and thicker sidewall...similar to a Hiendau. My brother has a nomar changer but I let the shop do it. Both tires balanced with 4 weights.
The cross section is different. All my tires prior to the A3s had a sort of mushroom cross section with a tead that would be the "cap" and the sidewalls the "stem". The A3 has a much more rounded cross section and the tread blends in to the sidewall rather than having a distinct tread and sidewall area.
Advertising pictures of the tire do not do it justice. It looks like it was designed for our bikes. It just looks good...if a tire can have aesthetic value that is.
Some have reported noise, I ride with ear plugs and up to 80 mph I heard no difference from my old tires. I ran them up to triple digits and they seem to ride well. Our roads are still covered with sand and coal cinders and the tires are very predictable when they start to break traction. No wet riding on them yet. I do have a slight decel wobble with the A3 that is similar to how my bike acted with half worn A2s.
Some have reported the A3s pick up gravel. I did not experience this on the unimproved county roads by my house.
My initial impression is the tread wear is about equal to A2 and not quite as good as tourance.
I have never mounted touring rubber on my Strom, but the A3 seems to turn in much easier than the A2. I suspect they handle similar to a quality street only tire, but with a more aggressive look to them. The A3 is a great tire in the twisties.
I was one who first thought the A3 was a step in the wrong direction for Michelin and could not understand why they dropped the A2. I searched E-bay for some low mileage A2s without any luck. Given the choice, I would buy the A3 over the A2 without hesitation now and I am glad I took a gamble on them.
If the moderators see fit they can bury this in the big tire thread